The number 1,821,960 can be evenly divided by 1 2 3 4 5 6 7 8 9 10 12 14 15 18 20 21 24 27 28 30 35 36 40 42 45 54 56 60 63 70 72 84 90 105 108 120 126 135 140 168 180 189 210 216 241 252 270 280 315 360 378 420 482 504 540 630 723 756 840 945 964 1,080 1,205 1,260 1,446 1,512 1,687 1,890 1,928 2,169 2,410 2,520 2,892 3,374 3,615 3,780 4,338 4,820 5,061 5,784 6,507 6,748 7,230 7,560 8,435 8,676 9,640 10,122 10,845 13,014 13,496 14,460 15,183 16,870 17,352 20,244 21,690 25,305 26,028 28,920 30,366 32,535 33,740 40,488 43,380 45,549 50,610 52,056 60,732 65,070 67,480 75,915 86,760 91,098 101,220 121,464 130,140 151,830 182,196 202,440 227,745 260,280 303,660 364,392 455,490 607,320 910,980 and 1,821,960, with no remainder.
Since 1,821,960 cannot be divided by just 1 and 1,821,960, it is a composite number.